In the browning reaction occurring in foodstuffs there is an accumulation of carbonyl compounds as well as the production of protein- carbohydrate complexes. Data accumulated previously indicates that animals have extreme difficulty in the utilization of the protein- carbohydrate complexes. Although some portion of the moiety is absorbed, it appears that it is absorbed through the large intestine due to the action of microorganisms. Thus, the microorganisms responsible for the breakdown of this product will be investigated and the limited metabolism of the protein-carbohydrate complexes will be followed. A mixture of carbonyls (isopropanol extractable substances) derived from the browned fruit inhibits the growth of animals and causes extreme diarrhea. The individual compounds responsible for this physiological effect will be identified and their dose response relationship identified. Both the carbonyl compounds and the amino-sugar compounds appear to induce a change in the microsomal content of the livers of animals fed such a diet. The compounds responsible for the change in polysome content will be identified utilizing radioactive techniques. The relative effects of the production of toxic compounds during browning and changes in protein quality will be separated in a number of feeding experiments in order to determine the effect of each set of compounds.